4.3 Generic Strategies for an MPLS label distribution protocol Migration

A failure or an outage during an MPLS label distribution protocol migration, or simply misalignment with another protocol such as a coupled link-state IGP, can have severe consequences for MPLS-based applications.

Apart from defining the migration premises and performing proofs of concept, carrying out MPLS label distribution protocol migration activities requires additional thinking beyond the label distribution protocols themselves, due to other external dependencies that affect selection of the best MPLS label. Label selection is not determined by the label distribution protocols alone, but rather, by whoever picks the best route, leading to MPLS label binding with available distributed labels. In this sense, IGPs, BGP, static and direct routes, and other protocols injecting route information must be analyzed for label-binding purposes and must be considered together in a migration framework.